Definition of Mole

Mole: 1. In dermatology a mole is a pigmented spot on the skin. The medical term for mole is melanocytic nevus (a nevus composed of melanocytes). 2. In gynecology, a mass within the uterus formed of partly developed products of conception.
3. In biochemistry, the molecular weight of a substance. In more technical terms, a mole is the number of atoms in exactly 12 g of carbon-12. Mole in this sense is short for molecular weight.